4.13
External position control
IDN used
Meaning
IDN 32
Primary Operation Mode
IDN 53
Position Feedback Value 2 (External Feedback)
IDN 76
Position Data Scaling Type
IDN 79
Rotational Position Resolution
IDN 117
Resolution of Rotational Feedback 2 (External Feedback)
IDN 257
Multiplication Factor 2
IDN 121
Input Revolutions of Load Gear
IDN 122
Output Revolutions of Load Gear
IDN 123
Feed Constant
IDNP 3017
Position Feedback Type (ASCII: EXTPOS)
The resolution of the external encoder is the number of lines per revolution it can supply.
In standard configuration, the multiplication factor can remain 1. The resolution used via
sercos
®
is still set via IDN 79 for rotational and IDN 123 for linear scaling. The encoder
lines are then scaled to this resolution.
Example:
Motor encoder:
Resolver FBTYPE 0
External encoder: 5 V ROD encoder on plug X5 => EXTPOS 3
Position resolution:20bit via sercos
®
EXTPOS uses positive values for active control and negative values when the external
encoder is only to be read in.
If the external encoder is being used for active control, PFB0 is copied to PFB and the
motor encoder then only supplies position data via PRD. This is limited to one revolution
(like modulo), as it only contributes to the commutation.
Startup parameters
IDN
Name
Type
Value
S-0-0032
Main operating mode
UINT16
12 (0x000C)
S-0-0055
Position polarities
UINT16
0 (0x0000)
S-0-0076
Type of scaling for position data
UINT16
74 (0x004A)
S-0-0117
Resolution of Rotational Feedback 2
UINT32
500
S-0-0079
Rotational position resolution
UINT32
1048576
P-0-3017
Position Feedback Type
INT16
3
sercos
®
for S300/S700
121
Kollmorgen
04/2016
Appendix
